Prognostic value of electrophysiologic studies in Brugada syndrome.

A decade has passed since Pedro and Joseph Brugada (1) discovered an electrocardiographic (ECG) marker for sudden cardiac death in a subset of patients with idiopathic ventricular fibrillation (VF) characterized by ST-segment elevation in the right precordial leads (V1 to V3) with a right bundle branch block pattern. This clinical entity, quickly recognized as the Brugada syndrome, has drawn widespread attention from cardiologists, electrophysiologists and arrhythmia scholars throughout the world. We have now learned that the Brugada syndrome is a familial disease with an autosomal dominant transmission with incomplete penetrance (2). In addition, the genetic cause of the syndrome has been identified as a mutation in the cardiac sodium channel gene, SCN5A (3). The clinical presentation of the Brugada syndrome is nocturnal sudden death due to VF occurring mostly in men. The syndrome is endemic in Southeast Asia and Japan, where it is also known as sudden unexplained death syndrome, and the incidence has been estimated to range between 5 and 66 events per 100,000 people (2,4). However, the true incidence may yet to be realized as more physicians become cognizant of the ECG pattern associated with the Brugada syndrome and hence, diagnose more cases.